Individual study: Hormonal induction of spawning in 4 species of frogs by coinjection with a gonadotropin-releasing hormone agonist and a dopamine antagonist
Trudeau V.L., Somoza G.M., Natale G.S., Pauli B., Wignall J., Jackman P., Doe K. & Schueler F.W. (2010) Hormonal induction of spawning in 4 species of frogs by coinjection with a gonadotropin-releasing hormone agonist and a dopamine antagonist. Reproductive Biology and Endocrinology, 8, 1-9
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Use hormone treatment to induce sperm and egg release during captive breeding
A replicated, controlled study in 2008 of captive frogs in Ottawa, USA (Trudeau et al. 2010) found that injection with a gonadotropin-releasing hormone (GnRH) agonist and a dopamine antagonist was effective at inducing egg production. After one week in captivity GnRH-A (0.4 μg/g body weight) and metoclopramide (10 μg/g) was more effective at inducing egg production in northern leopard frogs Lithobates pipiens (100%) than GnRH-A and pimozide (10 μg/g; 50%), GnRH-B (0.4 μg/g) and pimozide (42%) or no treatment (0%). After one month in captivity, GnRH-A with 10 μg/g of metoclopramide was significantly more effective than with 5 μg/g (60 vs 44%). Out-of-season breeding was induced with GnRH-A and metoclopramide in five pairs, with 25% of females producing eggs (and metamorphs). Egg production (and metamorphs) was also induced in Argentine horned frog Ceratophrys ornate (1 pair), Cranwell's horned frog Ceratophrys cranwelli (1 pair) and escuercitos Odontophrynus americanus (10 males, 5 females). A week after collection in April, 12 female and 18 male leopard frogs were given one of four initial treatments. Controls were given saline and dimethyl sulfoxide. A month after collection, nine females and 15 males were given 0.4 μg/g GnRH-A and either 5 or 10 μg/g of metoclopramide, or were controls. Following collection in September, artificial overwintering was induced in eight females and 15 males. In October, males were primed with two injections of GnRH-A (0.025 then 0.05 μg/g a week later). Frogs were then injected with GnRH-A (0.4 μg/g) and metoclopramide (10 μg/g).